阅读说明：本技术 一种用于毫米波太赫兹频率的软波导及其性能测试装置 (Soft waveguide for millimeter wave terahertz frequency and performance testing device thereof ) 是由 张坤 屈丹丹 罗耕星 肖京华 彭林华 叶智军 王体兵 于 2020-12-08 设计创作，主要内容包括：本发明属于基于5G/7G技术的卫星通讯、电磁波传导元件或雷达设备技术领域,针对传统的制备方法已不能满足超精细微结构的要求,本发明公开了一种用于毫米波太赫兹频率的软波导及其性能测试装置和制备方法,所述软波管的内、外表面分布设置有若干个矩形波纹结构的外凹槽,且所述软波管的内截面设置为矩形空心的结构,软波管的矩形波纹设置为由大矩形管和小矩形管呈连续排布而成的结构；当硬度和韧性特定匹配时,外凹槽结构省去。本发明可快速制备高精度、微细结构软波管,实现传输超高频太赫兹电磁波；且制备周期短(几小时),相比于传统制芯去芯等方法,克服了成品率低、周期长缺点。可实现软波管和连接端头一体打印,便于与硬波导管连接。(The invention belongs to the technical field of satellite communication and electromagnetic wave conduction elements or radar equipment based on 5G/7G technology, and aims to solve the problem that the traditional preparation method cannot meet the requirement of a hyperfine microstructure, the invention discloses a flexible waveguide for millimeter wave terahertz frequency, a performance testing device and a preparation method thereof, wherein a plurality of outer grooves with rectangular corrugated structures are distributed on the inner surface and the outer surface of the flexible waveguide, the inner section of the flexible waveguide is set to be a rectangular hollow structure, and the rectangular corrugations of the flexible waveguide are set to be structures formed by continuously arranging large rectangular pipes and small rectangular pipes; when the hardness and toughness are specifically matched, the outer groove structure is omitted. The invention can rapidly prepare the high-precision micro-structure soft wave tube and realize transmission of the ultrahigh frequency terahertz electromagnetic wave; and the preparation period is short (several hours), and compared with the traditional core making and removing methods, the method overcomes the defects of low yield and long period. The soft wave tube and the connecting end can be integrally printed, and the connection with the hard wave tube is facilitated.)

1. The utility model provides a soft waveguide for millimeter wave terahertz frequency, its characterized in that, includes the soft wave pipe, the inside and outside surface distribution of soft wave pipe is provided with the outer recess of a plurality of rectangle ripple structure, just the interior cross-section of soft wave pipe sets up to the hollow structure of rectangle, and the rectangle ripple of soft wave pipe sets up to be the structure that forms of arranging in succession by big rectangular pipe and little rectangular pipe.

2. The flexible waveguide for the millimeter wave terahertz frequency according to claim 1, wherein the large rectangular tube is a hollow tube with a large rectangular inner section, and the hollow tube protrudes outwards along the outer wall of the flexible waveguide; the small rectangular tube is inwards sunken along the outer wall of the flexible waveguide to form a hollow tube with a small rectangular inner section; an outer groove is formed between the adjacent large rectangular tubes on the outer surface of the soft wave tube.

3. The flexible waveguide for the millimeter wave terahertz frequency according to claim 1, wherein the outer wall of the large rectangular tube protrudes and extends outwards along the outer wall of the small rectangular tube to form an outer flange, and the corners of the outer flange are provided with arc-shaped smooth wall surfaces; the inner wall of the small rectangular pipe protrudes outwards along the inner wall of the large rectangular pipe to form an inner flange; an inner groove is formed between the inner flange and the inner wall of the large rectangular pipe.

4. The flexible waveguide for the millimeter wave terahertz frequency according to claim 1, wherein the flexible waveguide has the detail size requirements of repeated bending of a large rectangle and a small rectangle, the E-plane bending radius of the flexible waveguide is set to be 48-96mm, the H-plane bending radius is set to be 96-192mm, and the flexible waveguide is suitable for a 74-330GHz high-frequency band and has a transmission wavelength range of 30 micrometers-3 millimeters.

5. The flexible waveguide for millimeter wave terahertz frequencies according to claim 1, wherein the width of the outer groove of the flexible waveguide is set to be 0.3-0.9mm, the depth of the outer groove is not more than 1/10 transmission wavelength, and the ratio of the depth and the width of the outer groove is not less than 1; the ratio of the length of the soft wave tube to the width of the inner section of the soft wave tube is not less than 50.

6. The flexible waveguide for the millimeter wave terahertz frequency according to claim 1, wherein the connection mode of the large rectangle and the small rectangle of the flexible waveguide is set to be integrally formed, and the flexible waveguide is printed by adopting a flexible material or a soft-hard interphase rubber-like material; the end part of the soft wave tube is provided with a flange plate which is connected with the hard wave tube through a flange, and the flange plate is made of copper alloy or aluminum alloy plated with copper/nickel.

7. The performance testing device for the flexible waveguide of millimeter wave terahertz frequency according to any one of claims 1 to 6, comprising a fixing plate and a testing mechanism a and a testing mechanism b mounted on the fixing plate,

the testing mechanism a comprises a control lever a, a semicircular shaft a and a pull rod a, the control lever a is erected on two sides of the semicircular shaft a, the pull rod a is further arranged at one side end of the semicircular shaft a, and the flexible waveguide is controlled by the pull rod a and the control lever a to be subjected to bending testing along the semicircular shaft a;

the testing mechanism b comprises an operating rod b, a semicircular shaft b and a pull rod b, the operating rod b is erected on two sides of the semicircular shaft b, the pull rod b is further arranged at one side end of the semicircular shaft b, and the flexible waveguide is controlled by the pull rod b and the operating rod b to be subjected to bending testing along the semicircular shaft b.

8. The device for testing the performance of the flexible waveguide at the terahertz frequency of the millimeter waves as claimed in claim 7, wherein the semicircular axis a and the semicircular axis b are both configured as a semicircular cylinder structure cut along a longitudinal plane, the horizontal planes of the semicircular axis a and the semicircular axis b are fixedly arranged on the fixing plate, and the arc-shaped curved surface structures of the semicircular axis a and the semicircular axis b are bending test surfaces.

9. The performance testing device for the flexible waveguide of millimeter wave terahertz frequency according to claim 7 or 8, characterized in that the specific operation comprises the following steps:

(1) inserting one end of a soft waveguide to be tested, and keeping the E surface of the soft waveguide and the H surface of the soft waveguide parallel to the tangent line of the semicircular axis a;

(2) rotating the pull rod a to enable the flexible waveguide to be in contact with the semicircular shaft a and clamped;

(3) uniformly and smoothly rotating the operating rod a to bend the flexible waveguide at a rate of 5 ° per second according to the bending specification of the flexible waveguide;

(4) turning the soft waveguide to be tested for 180 degrees, and simultaneously keeping the E surface of the soft wave tube and the H surface of the soft wave tube parallel to the tangent line of the semicircular axis b;

(5) rotating the pull rod b to make the flexible waveguide contact with the semicircular shaft b and clamp the flexible waveguide;

(6) uniformly and smoothly rotating the operating rod b to bend the flexible waveguide at a rate of 5 ° per second according to the bending specification of the flexible waveguide;

(7) repeating the operations of the steps (1) to (6) 4 times.

10. The method for preparing the flexible waveguide for the terahertz frequency of the millimeter waves according to any one of claims 1 to 6, which is characterized by comprising the following steps: (1) selecting flexible materials or soft and hard alternate rubber materials to be mixed according to the repeated bending requirement of the soft wave tube to be printed to obtain a printing material of the soft wave tube;

(2) spraying a printing material of a soft wave tube on the upper layer of the tray, wherein the thickness of a horizontal construction layer is as thin as 14 micrometers, and each layer is 55 micrometers in an ultra-high speed mode;

(3) after spraying, the mixture is immediately cured by an ultraviolet lamp to finish the rapid forming of the soft wave tube.

Technical Field

The invention belongs to the technical field of satellite communication and electromagnetic wave conduction elements or radar equipment based on a 5G/7G technology, and particularly relates to a flexible waveguide for millimeter wave terahertz frequency, a performance testing device and a preparation method thereof.

Background

The soft waveguide belongs to an electromagnetic wave conduction element, and an inner cavity conducts 74-330GHz electromagnetic waves, so that the surface is required to be smooth. The two ends are mechanically connected with the copper hard waveguide by flanges. Because the spatial position of the copper hard waveguides at two ends has random deviation of about 50 mm, the copper hard waveguides are generally required to be of a corrugated structure so as to meet the requirement of flexible installation.

The traditional material of the soft waveguide is a metal material (TU1 or TU2 oxygen-free copper, or H96, H90 or H62 copper alloy), the structural form is limited by the preparation technology, and the traditional preparation method comprises the steps of copper electroplating of an aluminum core (removing the aluminum core), mechanical forming, hydraulic forming and the like. In the prior art, the aluminum core is in a circular tube structure, and arc-shaped notches are arranged at two side ends of the cross section of the aluminum core, so that the aluminum core copper electroplating method has the disadvantages of poor dimensional precision, low efficiency and long period; the mechanical forming technologies such as interlocking type and butt welding type have the defects of sparking, welding marks and the like; the hydraulic forming technology has the advantages of uniform pressure, high batch production efficiency and the like, but is limited by low-frequency band electromagnetic wave transmission because of being only suitable for circular tube production and cannot be used for terahertz frequency bands.

In order to meet the requirement of high centralization of a terahertz system, various high-precision flexible waveguide designs exist at present, but the traditional preparation method cannot meet the requirement of a hyperfine microstructure. Therefore, how to develop a soft waveguide for millimeter wave terahertz frequency has important practical significance.

Disclosure of Invention

Aiming at the technical problem that the traditional preparation method in the prior art cannot meet the requirement of a hyperfine microstructure, the invention aims to provide a flexible waveguide for millimeter wave terahertz frequency, a performance testing device and a preparation method thereof.

The technical scheme adopted by the invention is as follows:

the utility model provides a soft waveguide for millimeter wave terahertz frequency, includes the soft wave pipe, the inside and outside surface distribution of soft wave pipe is provided with the outer recess of a plurality of rectangle ripple structure, just the interior cross-section of soft wave pipe sets up to the hollow structure of rectangle, and the rectangle ripple of soft wave pipe sets up to be the structure of arranging in succession and forming by big rectangular pipe and little rectangular pipe.

When the hardness and toughness are specifically matched, the outer groove structure is omitted.

The total external shape of the soft wave tube is rectangular, the size of the soft wave tube is 2.54 × 1.27mm-0.86 × 0.43mm, and the soft wave tube physically meets the requirement of high-frequency electromagnetic wave transmission.

Furthermore, the large rectangular tube protrudes outwards along the outer wall of the flexible waveguide and is extended to form a hollow tube with a large rectangular inner section; the small rectangular tube is inwards sunken along the outer wall of the flexible waveguide to form a hollow tube with a small rectangular inner section; an outer groove is formed between the adjacent large rectangular tubes on the outer surface of the soft wave tube.

Further, the outer wall of the large rectangular pipe protrudes outwards along the outer wall of the small rectangular pipe to form an outer flange, and the corner of the outer flange is provided with an arc-shaped smooth wall surface; the inner wall of the small rectangular pipe protrudes outwards along the inner wall of the large rectangular pipe to form an inner flange; an inner groove is formed between the inner flange and the inner wall of the large rectangular pipe.

Furthermore, the detailed size of the large rectangle and the small rectangle of the soft wave tube is required to be repeatedly bent, the bending radius of the E surface of the soft wave tube is set to be 48-96mm, the bending radius of the H surface of the soft wave tube is set to be 96-192mm, and the soft wave tube is suitable for a 74-330GHz high-frequency band and has a transmission wavelength range of 30 micrometers-3 millimeters.

Further, the width of an outer groove of the soft wave tube is set to be 0.3-0.9mm, the depth of the outer groove is not more than 1/10 transmission wavelength, and the ratio of the depth to the width of the outer groove is not less than 1; the ratio of the length of the soft wave tube to the width of the inner section of the soft wave tube is not less than 50.

Further, a sheath is arranged on the outer side of the soft wave tube, and the sheath is made of any one of neoprene, plastics, silicon rubber or fluorosilicone rubber.

Furthermore, the end part of the soft wave tube is provided with a flange plate which is connected with the hard wave tube through a flange, and the flange plate is made of copper alloy or aluminum alloy copper/nickel plating.

Furthermore, the connection mode of the big rectangle and the small rectangle of the soft wave tube is set to be integrally formed, the soft wave tube is printed by adopting a flexible material or a soft and hard alternate rubber material, and more specifically, any one or more of a tough resin, an ultra-tough resin or a hard resin is adopted.

A performance testing device for a millimeter wave terahertz frequency flexible waveguide comprises a fixed plate, a testing mechanism a and a testing mechanism b which are arranged on the fixed plate,

the testing mechanism a comprises a control lever a, a semicircular shaft a and a pull rod a, the control lever a is erected on two sides of the semicircular shaft a, the pull rod a is further arranged at one side end of the semicircular shaft a, and the flexible waveguide is controlled by the pull rod a and the control lever a to be subjected to bending testing along the semicircular shaft a;

the testing mechanism b comprises an operating rod b, a semicircular shaft b and a pull rod b, the operating rod b is erected on two sides of the semicircular shaft b, the pull rod b is further arranged at one side end of the semicircular shaft b, and the flexible waveguide is controlled by the pull rod b and the operating rod b to be subjected to bending testing along the semicircular shaft b.

Further, semicircle axle a and semicircle axle b all set up to the halfcylinder structure of following the longitudinal plane segmentation, and the horizontal plane of semicircle axle a and semicircle axle b is fixed to be set up on the fixed plate, and the arc curved surface structure of semicircle axle a and semicircle axle b is crooked test surface.

A performance testing device for a flexible waveguide with millimeter wave terahertz frequency specifically comprises the following steps:

(1) inserting one end of a soft waveguide to be tested, and keeping the E surface of the soft waveguide and the H surface of the soft waveguide parallel to the tangent line of the semicircular axis a;

(2) rotating the pull rod a to enable the flexible waveguide to be in contact with the semicircular shaft a and clamped;

(3) uniformly and smoothly rotating the operating rod a to bend the flexible waveguide at a rate of 5 ° per second according to the bending specification of the GJB1510A-2009 for flexible waveguides;

(4) turning the soft waveguide to be tested for 180 degrees, and simultaneously keeping the E surface of the soft wave tube and the H surface of the soft wave tube parallel to the tangent line of the semicircular axis b;

(5) rotating the pull rod b to make the flexible waveguide contact with the semicircular shaft b and clamp the flexible waveguide;

(6) uniformly and smoothly rotating the operating rod b to bend the flexible waveguide at a rate of 5 ° per second according to the bending specification of the GJB1510A-2009 for flexible waveguides;

(7) repeating the operations of the steps (1) to (6) 4 times.

A preparation method of a soft waveguide for millimeter wave terahertz frequency specifically comprises the following steps: (1) selecting flexible materials or soft and hard alternate rubber materials to be mixed according to the repeated bending requirement of the soft wave tube to be printed to obtain a printing material of the soft wave tube;

(2) spraying a printing material (liquid photosensitive resin) of a soft wave tube on the upper layer of the tray, wherein the horizontal building layer is as thin as 14 microns, and each layer is 55 microns in a super high speed mode;

(3) after spraying, the mixture is immediately cured by an ultraviolet lamp to finish the rapid forming of the soft wave tube.

The printing material of the soft wave tube in the step (1) is any one or more of tough resin, super-tough resin or hard resin, the used material is a rubber-like photosensitive resin material, and the printing material is selected and mixed according to the design requirement.

The invention has the beneficial effects that:

the total external dimension of the soft wave tube is 2.54 x 1.27mm-0.86 x 0.43mm, and the preparation method is the light-cured liquid photosensitive resin, so that the high-precision and fine-structure soft wave tube can be rapidly prepared, and the transmission of the ultrahigh-frequency terahertz electromagnetic wave is realized. According to the performance testing device for the flexible waveguide with the millimeter wave terahertz frequency, a combination mode that the semicircular shaft a and the semicircular shaft b are matched in a cooperative mode is adopted, the structure is in a geometric shape, the processing is convenient, meanwhile, the performance testing of the flexible waveguide can be realized, the testing precision can be accurately regulated and controlled, the bending testing operation is convenient, the reuse rate is high, the device can be fully applied to the mechanical property testing of different printing materials, and the applicability is wide.

The method for preparing the soft wave tube belongs to a method from outside to inside, greatly reduces the preparation period, only needs a few hours, and overcomes the defects of low yield and long period compared with the traditional method of firstly preparing the aluminum core, electroplating a metal functional layer on the aluminum core and then dissolving and removing the core.

The soft wave tube and the connecting end can be integrally printed, and the connection with the hard wave tube is facilitated.

Drawings

FIG. 1 is a schematic view of the overall structure of a flexible waveguide according to the present invention;

FIG. 2 is a schematic view of the overall structure of the flexible waveguide with flange according to the present invention;

FIG. 3 is a schematic view of the overall structure of the flexible waveguide of the present invention;

FIG. 4 is a schematic structural diagram of a thin-walled flexible waveguide according to the present invention;

FIG. 5 is a schematic diagram of the internal cross-sectional structure of the thin-walled flexible waveguide of the present invention;

FIG. 6 is a schematic structural diagram of a thick-walled flexible waveguide according to the present invention;

FIG. 7 is a schematic diagram of the internal cross-sectional structure of a thick-walled flexible waveguide according to the present invention;

FIG. 8 is a schematic structural diagram of a device for testing the performance of a flexible waveguide according to the present invention;

FIG. 9 is a side view of a device for testing the performance of a flexible waveguide according to the present invention;

FIG. 10 is a top view of the device for testing the performance of the flexible waveguide of the present invention;

wherein, 1, outer groove; 2. a small rectangular tube; 3. a large rectangular tube; 4. a joystick a; 5. a semicircular axis a; 6. a pull rod a; 7. a joystick b; 8. a semicircular axis b; 9. and a pull rod b.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

Example 1

As shown in fig. 1 to 7, a flexible waveguide for millimeter wave terahertz frequency includes a flexible waveguide, where the inner and outer surfaces of the flexible waveguide are distributed with a plurality of outer grooves with rectangular corrugated structures, the inner cross section of the flexible waveguide is a rectangular hollow structure, and the rectangular corrugations of the flexible waveguide are structures formed by continuously arranging large rectangular tubes and small rectangular tubes;

when the hardness and toughness are specifically matched, the outer groove structure is omitted.

As shown in fig. 4-7, the large rectangular tube is extended and protruded outwards along the outer wall of the flexible waveguide to be a hollow tube with a large rectangular inner section; the small rectangular tube is inwards sunken along the outer wall of the flexible waveguide to form a hollow tube with a small rectangular inner section; an outer groove is formed between the adjacent large rectangular tubes on the outer surface of the soft wave tube.

As shown in fig. 4-7, the outer wall of the large rectangular tube protrudes and extends outwards along the outer wall of the small rectangular tube to form an outer flange, and the corners of the outer flange are provided with arc-shaped smooth wall surfaces; the inner wall of the small rectangular pipe protrudes outwards along the inner wall of the large rectangular pipe to form an inner flange; an inner groove is formed between the inner flange and the inner wall of the large rectangular pipe.

The cooperative matching of the outer groove and the inner groove meets the requirement on hardness, effectively improves the bending toughness of the flexible waveguide and meets the requirement on high-frequency electromagnetic wave transmission.

The total external shape of the soft wave tube is rectangular, the size of the soft wave tube is 2.54 × 1.27mm-0.86 × 0.43mm, and the soft wave tube physically meets the requirement of high-frequency electromagnetic wave transmission.

According to another embodiment of the invention, the detailed dimension of the large rectangle and the small rectangle of the soft wave tube is required to be repeatedly bent, the E-surface bending radius of the soft wave tube is set to be 48-96mm, the H-surface bending radius is set to be 96-192mm, the soft wave guide soft wave tube structure and the sheath are prepared by adopting high-precision photocuring or laser sintering 3D printing, the material and the structure of the wave guide have adjustability, the soft wave guide soft wave tube structure is suitable for 74-330GHz high-frequency bands, and the transmittable wavelength range is 30 micrometers-3 millimeters.

In another embodiment of the invention, the width of the outer groove of the soft wave tube is set to be 0.3-0.9mm, the depth of the outer groove is not more than 1/10 transmission wavelength, and the ratio of the depth and the width of the outer groove is not less than 1; the ratio of the length of the soft wave tube to the width of the inner section of the soft wave tube is not less than 50.

As shown in fig. 1, the width of the outer groove is 0.4mm, and the corrugation width of the soft wave tube is 0.3 mm; section a-a ratio 5: 1, the wall thickness of the small rectangular tube is 0.05mm, the length is 2.38mm, and the width is 1.04 mm; section B-B ratio 5: 1, the large rectangular tube has a wall thickness of 0.05mm, a length of 2.96mm and a width of 1.32 mm.

The flexible waveguide soft wave tube structure is prepared by adopting high-precision photocuring or laser sintering 3D printing, the width of an outer groove is set to be 0.3-0.9mm, the depth of the outer groove is not more than 1/10 transmission wavelength, and the ratio of the depth to the width of the outer groove is not less than 1. The ratio of the length of the soft wave tube to the width of the inner section of the soft wave tube is not less than 50. Taking a flexible waveguide for transmitting 74-112GHz and 3mm wavelength as an example, the structure is shown in fig. 1, 3, 4, 5, 6 and 7, and the rectangular corrugation is formed by continuously forming a large rectangle and a small rectangle.

As shown in fig. 7, the length of the outer wall of the large rectangular tube is L1 ═ 3.451mm, and the length of the inner flange formed by the inner wall of the small rectangular tube protruding outward along the inner wall of the large rectangular tube is L2 ═ 0.172 mm.

In another embodiment of the present invention, a sheath is disposed outside the flexible wave tube, and the sheath is made of any one of neoprene, plastic, silicon rubber or fluorosilicone rubber.

In another embodiment of the present invention, as shown in fig. 2, the end of the soft wave tube is provided with a flange, and the flange is connected with the hard wave tube through a flange, and the flange is made of copper/nickel alloy or aluminum alloy.

The end head connection mode is replaced by other modes such as ultraviolet curing and the like.

In another embodiment of the present invention, the connection mode of the large rectangle and the small rectangle of the soft wave tube is set to be integrally formed, the soft wave tube is printed by using a flexible material or a soft and hard rubber-like material, and more specifically, any one or more of a tough resin, an ultra-tough resin, or a hard resin is used. The mechanical properties of the three materials are shown in table 1.

Table 1: mechanical properties of three printing materials

In another embodiment of the present invention, a method for manufacturing a flexible waveguide for millimeter wave terahertz frequency specifically includes the following steps: (1) selecting flexible materials or soft and hard alternate rubber materials to be mixed according to the repeated bending requirement of the soft wave tube to be printed to obtain a printing material of the soft wave tube;

(2) spraying a printing material (liquid photosensitive resin) of a soft wave tube on the upper layer of the tray, wherein the horizontal building layer is as thin as 14 microns, and each layer is 55 microns in a super high speed mode;

(3) after spraying, the mixture is immediately cured by an ultraviolet lamp to finish the rapid forming of the soft wave tube.

The printing material of the soft wave tube in the step (1) is any one or more of tough resin, super-tough resin or hard resin, the used material is a rubber-like photosensitive resin material, and the printing material is selected and mixed according to the design requirement.

In another embodiment of the present invention, as shown in fig. 8, 9 and 10, a performance testing apparatus for a flexible waveguide of millimeter wave terahertz frequency comprises a fixed plate, and a testing mechanism a and a testing mechanism b mounted on the fixed plate,

the testing mechanism a comprises a control lever a, a semicircular shaft a and a pull rod a, the control lever a is erected on two sides of the semicircular shaft a, the pull rod a is further arranged at one side end of the semicircular shaft a, and the flexible waveguide is controlled by the pull rod a and the control lever a to be subjected to bending testing along the semicircular shaft a;

the testing mechanism b comprises an operating rod b, a semicircular shaft b and a pull rod b, the operating rod b is erected on two sides of the semicircular shaft b, the pull rod b is further arranged at one side end of the semicircular shaft b, and the flexible waveguide is controlled by the pull rod b and the operating rod b to be subjected to bending testing along the semicircular shaft b.

Semicircle axle a and semicircle axle b all set up to the halfcylinder structure along the longitudinal plane segmentation, and the horizontal plane of semicircle axle a and semicircle axle b is fixed to be set up on the fixed plate, and the arc curved surface structure of semicircle axle a and semicircle axle b is crooked test surface.

On the basis of the above embodiment, a performance testing apparatus for a flexible waveguide with a millimeter wave terahertz frequency specifically includes the following steps:

(1) inserting one end of a soft waveguide to be tested, and keeping the E surface of the soft waveguide and the H surface of the soft waveguide parallel to the tangent line of the semicircular axis a;

(2) rotating the pull rod a to enable the flexible waveguide to be in contact with the semicircular shaft a and clamped;

(3) uniformly and smoothly rotating the operating rod a to bend the flexible waveguide at a rate of 5 ° per second according to the bending specification of the GJB1510A-2009 for flexible waveguides;

(4) turning the soft waveguide to be tested for 180 degrees, and simultaneously keeping the E surface of the soft wave tube and the H surface of the soft wave tube parallel to the tangent line of the semicircular axis b;

(5) rotating the pull rod b to make the flexible waveguide contact with the semicircular shaft b and clamp the flexible waveguide;

(6) uniformly and smoothly rotating the operating rod b to bend the flexible waveguide at a rate of 5 ° per second according to the bending specification of the GJB1510A-2009 for flexible waveguides;

(7) repeating the operations of the steps (1) to (6) 4 times.

The above description is not meant to be limiting, it being noted that: it will be apparent to those skilled in the art that various changes, modifications, additions and substitutions can be made without departing from the true scope of the invention, and these improvements and modifications should also be construed as within the scope of the invention.